Murder and voluntary manslaughter

What is Murder?

  • Murder is when a human of sound mind and of the age of 10years and above kill another human being unlawfully.
  • In order for murder to have been committed the prosecution must prove that both the men rea and actus reus were present.

Actus Reus

  • Actus reus is defined by law as the prohibited conduct or behaviour that the law seeks to prevent.
  • Actus reus is commonly referred to as the ‘guilty act’, the actus reus includes all aspects of the crime except the accused’s mental state.
  • In most cases the actus reus is simply just the act.

What is Unlawful Killing?

Unlawful killing states that a person commits murder if the killing is unlawful. If a defence of self-defence was raised this would make the killing lawful which would not constitute murder.


The act (or omission) of the defendant must have been the legal cause of the death of the victim. Causation must be established.

  1. Killing
  • Causation is relevant
  1. Human Being
  • The victim must be a living human being. The victim must be a human being alive at  the time of the defendants actions.
  1. “Under the Queens Peace”
  • This applies to everyone except enemy aliens in wartime.

Mens Rea of Murder and Malice Aforethought

The mens rea of murder is ‘Malice aforethought’ or Intention.

‘Malice Aforethought’ is used to describe the intention to kill or cause GBH.

Previously the House of Lords held that nothing less than intention to kill or cause grievous bodily harm (G.B.H.) would constitute malice aforethought.

  1. Intention to Kill

Intention is the state of the mind of the person who intends to bring about a particular consequence. Intention is one of the main forms of mens rea.

Murder is a crime of specific intent. In this context intention includes direct or oblique intent. Direct intent covers the situation where the defendant desired the death and oblique intent is the situation where the victims’ death is foreseen by the defendant as virtually certain.

  1. Intention to Cause G.B.H.

A defendant can be convicted of murder if it has been established that he/she had intended to kill, or had intended to cause grievous bodily harm to the victim. The intention to cause G.B.H. has been accepted as sufficient mens rea for murder. This is due to the person willingly wanting to inflict G.B.H. and in doing so takes the risk that the victim may die.

What is G.B.H.?

  • Grievous bodily harm is defined as ‘really serious harm’ to another human being.
  • The injury does not necessarily need to be permanent damage or life-threatening, however, what may be serious to one person may not be deemed serious to another.

What is Common Assault?

Common assault need to be caused by physical violence. No harm whatsoever need be inflicted, spitting and verbal assault is included in common assault.


  • Murder carries out a mandatory life sentence,
  • Minimum terms of imprisonment are set out in the Criminal Justice Act 2003, section 269 and Schedule.21, applying to murders on or after December 18, 2003.


  • Manslaughter is the crime of killing a human being without the mens rea of malice aforethought, or in circumstances which do not amount to murder.

Gross Negligence Manslaughter

  • Gross negligence manslaughter is a form of involuntary manslaughter where the defendant has supposedly acted lawfully.
  • Involuntary manslaughter may arise where the defendant has caused the death, however,
  • The death was not intended,
  • Neither the intention to cause serious bodily harm (G.B.H) was intended by the defendant.
  • Therefore, the mens rea of murder is not satisfied.

Constructive Manslaughter

  • Constructive manslaughter exists where the defendant commits an unlawful dangerous act which ultimately leads to the death of a human
  • If the defendant would be to commit a lawful act which results in death this may amount to gross negligence manslaughter.

The offence of constructive manslaughter can be broken down into three elements:

  1. There must be an unlawful act
  2. The unlawful act must be dangerous
  3. The unlawful dangerous act must cause death.

Definition of Voluntary Manslaughter

  • Voluntary manslaughter is when the defendant kills with the mens rea for murder
  • However, the defendant will only be convicted of voluntary manslaughter if one of the partial defences to murder applies. The two partial defences to murder are:
  • Diminished Responsibility or
  • Loss of Control.

Diminished Responsibility

Both the actus reus and the mens rea of murder are satisfied but if the defendant can prove on a balance of probabilities that he/she was suffering from diminished responsibility at the time of the crime they will therefore not be convicted of murder by convicted of voluntary manslaughter.

In order for diminished responsibility the defendant must argue that although they broke the law by killing another human being they should not be held fully liable for the crime due to their mental functions being impaired.

The burden is on the defendant to prove the defence on a balance of probabilities.


Duress are threats of:

  • Death and
  • Physical violence,
  • Either immediately or
  • Future violence that is used to induce a person to act against his or her will.
  • Duress is a complete defence to all crimes with the exception of murder, attempted and some forms of treason, to which duress will provide no defence at all.
  • A person may be able to avoid the consequences of their actions under the law if they were performed whilst under duress.


Anna goes to the supermarket and says to Peter “If you do not steal all the money from the tills I will shoot you in the head”.

This example is clear-cut. The defendant effectively has no choice.

Loss of Control

(Formerly provocation)

The common law defence of Provocation was replaced by a new partial defence of Loss of Control. The Act sets out a two-limbed approach;

  1. The first will apply where the defendant kills after suffering a loss of self-control attributable to fear of serious violence from the deceased,
  2. The second approach will apply where the loss of self-control can be attributed to acts done or things have been said which constituted circumstances of an extremely grave character and which caused the defendant to have a justifiable sense of being seriously wronged.

Self-Defence - Use of force

Where excessive force is used, provocation would provide a defence to murder, therefore reducing the conviction to manslaughter.

At common law a defence of self-defence allows a person to use reasonable force to;

  1. Defend themselves from an attack
  2. Prevent an attack from another person or persons
  3. Defend his or her properties

The use of excessive force or use of a firearm cannot be used as self-defence when protecting ones property. The use of these excessive forces will ultimately void any defence of self-defence therefore if the force leads to death there will be no liable self-defence recognised by law.

 “A person may use such force as is reasonable in the circumstances in the prevention of crime, or in effecting or assisting in the lawful arrest of offenders or suspected offenders or of persons unlawfully at large”.

However, if a person uses excessive force this indicates that they acted unreasonably in the circumstances, therefore, there will be no valid defence and the defendant will be liable for murder.

Self-Defence - Mistake

  • It is possible that a defendant may mistakenly believe himself to be threatened or that an offence is being committed by another person.
  • On the facts that they honestly believed them to be, therefore the defendant would be permitted to use a reasonable degree of force in the context of what is being perceived to be happening.

Self-Defence - Intoxication

  • When a person is voluntarily intoxicated and mistakenly believes that the actions of others are threatening, this may increase their defensive activity, however, the law does not provide a defence to a criminal charge.
  • Therefore, the defendant is liable for their actions and cannot rely on any defence.


While every effort has been made to ensure the accuracy of the information provided in this article, it does not constitute legal advice and cannot be relied upon as such. Each legal case and issue may have unique facts and circumstances, as a result legalally does not accept any responsibility for liabilities arising as a result of reliance upon the information provided. For further help and guidance, you can always rely on and seek advice from our experienced lawyers.

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